Kukudro is an MS Word macro trojan dropper written in Visual Basic for Applications (VBA). The dropper has been spammed in various emails as my_Notebook.doc inside a zip archive. Once a user opens the document, it drops and runs a binary executable.
Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.
A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:
Check for the latest database updates
First check if your F-Secure security program is using the latest updates, then try scanning the file again.
Submit a sample
After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.
Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.
Exclude a file from further scanning
If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.
Note: You need administrative rights to change the settings.
When the infected Word document is opened, the macro code inside of it will be executed. It will decode a binary file from its code and drop it as 666inse_1.exe to the root of the C: drive. Then the macro will execute the dropped 666inse_1.exe file and end. The binary executable is a trojan downloader called Small.dcu.
Please note that you are using Office 2003 or later the macro will be executed only if macros have been enabled from Word's security settings. Otherwise, the trojan uses a vulnerability in MS Word 97, 2000 and XP and will run although macros are disabled. You can find more about this vulnerability here: https://www.microsoft.com/technet/security/Bulletin/MS01-034.mspx.